Wire harness unit

ABSTRACT

A wire harness unit including: a plurality of conductive paths for conducting electricity between in-vehicle devices; and a cooling tube through which a coolant is able to flow for cooling the plurality of conductive paths, wherein: the plurality of conductive paths include a first conductive path and a second conductive path parallel with the first conductive path, the first conductive path includes a first tubular conductor that is conductive and hollow, the second conductive path includes a second tubular conductor that is conductive and hollow, and each of the first tubular conductor and the second tubular conductor includes a first end and a second end that is on an opposite side to the first end.

BACKGROUND

The present disclosure relates to a wire harness unit.

Conventionally, wire harnesses installed in vehicles such as hybrid carsand electric cars electrically connect a plurality of electrical devicesto each other. Also, in electric cars, vehicles and ground facilitiesare connected to each other by a wire harness, and a power storagedevice installed in the vehicle is charged by the ground facility. As aresult of a voltage supplied through the wire harness being high, theamount of heat generated by the wire harness is increased. For thisreason, configurations for cooling wire harnesses have been proposed.

For example, JP 2019-115253A discloses a wire harness provided with acoated wire, an inner tube that covers the coated wire, and an outertube that covers the inner tube with a predetermined space therebetween,in which a circulation path for a coolant is formed between the innertube and the outer tube. The circulation path is formed by inner andouter tubes that are separate from the coated wire, and the coated wireis disposed radially inward of the circulation path.

SUMMARY

Incidentally, in the wire harness disclosed in JP 2019-115253A, thecirculation path (a path along which the coolant flows) is disposedoutside the coated wire, and thus the coolant is far from the centralportion of the coated wire, which is the heat source. Accordingly, thereis room for improvement in terms of cooling efficiency of the coatedwire.

An exemplary aspect of the disclosure provides a wire harness unitcapable of improving cooling efficiency.

A wire harness unit that is an aspect of the present disclosure includesa plurality of conductive paths for conducting electricity betweenin-vehicle devices; and a cooling tube through which a coolant is ableto flow for cooling the plurality of conductive paths, wherein: theplurality of conductive paths include a first conductive path and asecond conductive path parallel with the first conductive path, thefirst conductive path includes a first tubular conductor that isconductive and hollow, the second conductive path includes a secondtubular conductor that is conductive and hollow, each of the firsttubular conductor and the second tubular conductor includes a first endand a second end that is on an opposite side to the first end, thecooling tube is more flexible than the first tubular conductor and thesecond tubular conductor, and is separate from the first tubularconductor and the second tubular conductor, and the cooling tubeincludes a turnback that links the first end of the first tubularconductor and the first end of the second tubular conductor, an inletconnected to the second end of the first tubular conductor, and anoutlet connected to the second end of the second tubular conductor.

According to a wire harness unit that is an aspect of the presentdisclosure, cooling efficiency can be improved.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic diagram showing a vehicle in which a wire harnessunit according to an embodiment is routed.

FIG. 2 is a schematic diagram of the wire harness unit.

FIG. 3 is a partial cross sectional view showing an overview of the wireharness unit.

FIG. 4 is a cross sectional view of the wire harness unit.

FIG. 5 is a diagram illustrating connection between a tubular conductor,a flexible conductor, and a terminal.

FIG. 6 is a schematic diagram showing a portion of the wire harnessunit.

FIG. 7 is a partial cross-sectional view showing an overview of a wireharness unit according to a variation.

FIG. 8 is a schematic diagram showing a portion of the wire harness unitaccording to the variation.

DETAILED DESCRIPTION OF EMBODIMENTS Description of Embodiments ofDisclosure

First, aspects of the present disclosure will be listed and described.

[1] A wire harness unit according to the present includes a plurality ofconductive paths for conducting electricity between in-vehicle devices,and a cooling portion for cooling the plurality of conductive paths, theplurality of conductive paths include a first conductive path and asecond conductive path that is parallel with the first conductive path,the first conductive path includes a first tubular conductor that isconductive and hollow, the second conductive path includes a secondtubular conductor that is conductive and hollow, each of the firsttubular conductor and the second tubular conductor includes a first endportion and a second end portion that is on the opposite side to thefirst end portion, the cooling portion is more flexible than the firsttubular conductor and the second tubular conductor, allows a coolant toflow therein, and includes a cooling tube that is separate from thefirst tubular conductor and the second tubular conductor, and thecooling tube includes a turnback tube that links the first end portionof the first tubular conductor and the first end portion of the secondtubular conductor, an inlet tube connected to the second end portion ofthe first tubular conductor, and an outlet tube connected to the secondend portion of the second tubular conductor.

According to this configuration, the coolant can flow inside the firsttubular conductor and the second tubular conductor and inside thecooling tube. For this reason, the first tubular conductor and thesecond tubular conductor can be cooled from the inside, thereby makingit possible to improve cooling efficiency. Moreover, since the coolingtube includes the turnback tube that links the first end portion of thefirst tubular conductor and the first end portion of the second tubularconductor, it is possible to reduce the number of inlets and outlets forthe coolant, specifically the number of inlet tubes and outlet tubes,and simplify the structure for connection to a pump, for example,compared with a case where the cooling tube does not include theturnback tube. In addition, for example, it is possible to reduce thenumber of inlet tubes and outlet tubes and the number of componentscompared with a case where the cooling tube does not include theturnback tube.

[2] It is preferable that the number of conductive paths included in theplurality of conductive paths is an even number.

According to this configuration, since the number of conductive pathsincluded in the plurality of conductive paths is an even number, theinlet and the outlet for the coolant, specifically the inlet tube andthe outlet tube, can be easily positioned close to each other. That isto say, a situation is avoided where the positions of the inlet tube andthe outlet tube for the coolant are spaced far apart from each otherwhen, for example, the number of conductive paths is three, which is anodd number, and the cooling tube includes two turnback tubes, and theoutlet tube is connected to the second end portion of the second tubularconductor via a third tubular conductor of a third conductive path.Thus, it is possible to easily set the positions of the inlet and theoutlet for the coolant close to each other, and to reduce a routingspace and the like for connection to a pump, for example.

[3] It is preferable that the wire harness unit further includes anexterior member for covering the conductive paths, the exterior memberincludes a tubular exterior member and a grommet that is connected to anend portion of the tubular exterior member, and the turnback tube isdisposed inside the grommet.

According to this configuration, since the turnback tube is disposedinside the grommet, it is possible to easily house the turnback tube,for example. Even in a case where, for example, the turnback tube isconfigured such that it cannot be sharply bent, and a large space isrequired, such a case can be easily addressed without increasing theentire size of the tubular exterior member. Moreover, for example, ifthe grommet is shaped such that the size thereof increases toward amember that is connected to the grommet, the turnback tube can be easilyhoused in a large space.

[4] It is preferable that the wire harness unit further includesprotective layers that respectively cover inner circumferential surfacesof the first tubular conductor and the second tubular conductor.

According to this configuration, since the protective layers thatrespectively cover the inner circumferential surfaces of the firsttubular conductor and the second tubular conductor are provided, theprotective layers make it possible to prevent a coolant that is suppliedto the inside of the first tubular conductor and the second tubularconductor from coming into direct contact with the inner circumferentialsurfaces of the first tubular conductor and the second tubularconductor.

[5] It is preferable that the first conductive path and the secondconductive path each include a flexible conductor and a terminal, theflexible conductor includes a first end portion that is electricallyconnected to the first tubular conductor or the second tubularconductor, and a second end portion that is electrically connected tothe terminal, and the flexible conductor is more flexible than the firsttubular conductor and the second tubular conductor.

According to this configuration, due to end portions of the firsttubular conductor and the second tubular conductor being connected tothe flexible conductors, dimensional tolerance of the conductive pathscan be absorbed. Further, this configuration is a counter measureagainst swinging generated while a vehicle is travelling.

[6] It is preferable that each of the first tubular conductor and thesecond tubular conductor is longer than the flexible conductor.

According to this configuration, since each of the first tubularconductor and the second tubular conductor is longer than the flexibleconductor, the sections where heat exchange takes place between thecoolant and the first tubular conductor and the second tubular conductorare long, and the first tubular conductor and the second tubularconductor can be further cooled.

[7] It is preferable that the wire harness unit further includes anelectromagnetic shield member for covering at least a portion of thecooling tube, the first tubular conductor, and the second tubularconductor, the electromagnetic shield member is a braided member formedby braiding metal strands, and the cooling tube extends through thebraided member.

According to this configuration, both the shielding properties forsuppressing electromagnetic noise radiation from the conductive pathsand an improvement in the ease of assembly of the cooling portion can beachieved.

[8] It is preferable that the wire harness unit further includes anexterior member for covering the conductive paths, and the exteriormember includes a tubular exterior member and a grommet connected to anend portion of the tubular exterior member, and the cooling tube extendsthrough the grommet.

According to this configuration, since the cooling tube extends throughthe grommet and is led out to the outside, a decrease in the waterblocking properties of the wire harness unit can be suppressed.

Description of Embodiments of Disclosure

Specific examples of a wire harness unit according to the presentdisclosure will be described below with reference to the drawings. Notethat, in the drawings, parts of the configurations may be shown in anexaggerated or simplified manner for convenience of description.Moreover, dimensional ratios of various portions may be different fromactual dimensional ratios. “Parallel” and “orthogonal” in the presentspecification include not only being exactly parallel and orthogonal butalso approximately parallel and orthogonal within a range in which theoperation and effects of the present embodiment can be achieved. Thepresent disclosure is not limited to the embodiments disclosed herein,but is defined by the claims, and intended to include all modificationswithin the meaning and the scope equivalent thereof.

Overview Configuration of Wire Harness Unit 10

A wire harness unit 10 shown in FIG. 1 electrically connects twoin-vehicle devices installed in a vehicle V. The vehicle V is, forexample, a hybrid car, an electric car, or the like. The wire harnessunit 10 includes conductive paths 11 for electrically connecting anin-vehicle device M1 and an in-vehicle device M2, and an exterior member60 for covering the conductive paths 11. The conductive paths 11 arerouted, for example, from the in-vehicle device M1 to the in-vehicledevice M2 so that portions thereof in a lengthwise direction pass underthe floor of the vehicle V. With regard to examples of the in-vehicledevice M1 and the in-vehicle device M2, the in-vehicle device M1 is aninverter installed toward the front side of the vehicle V, and thein-vehicle device M2 is a high-voltage battery installed on the rearside of the vehicle V relative to the in-vehicle device M1. Thein-vehicle device M1 serving as an inverter is connected to a motor (notshown) for driving the wheels serving as a motive power source forcausing the vehicle to travel, for example. The inverter generates ACpower from DC power from the high-voltage battery, and supplies the ACpower to the motor. The in-vehicle device M2, which is a high-voltagebattery, is a battery capable of supplying a voltage of at least 100 V,for example. In other words, the conductive paths 11 of the presentembodiment constitute a high-voltage circuit that enables high-voltageexchange between the high-voltage battery and the inverter.

Detailed Configuration of Wire Harness Unit 10

As shown in FIGS. 2, 3, and 4 , the wire harness unit 10 includes aplurality of conductive paths 11, a cooling tube 40, an electromagneticshield member 50 (electromagnetic shield), an exterior member 60(exterior cover), and connectors 71 and 72. As shown in FIGS. 4 and 6 ,the plurality of conductive paths 11 include a first conductive path 20and a second conductive path 30 that is parallel with the firstconductive path 20.

As shown in FIGS. 3 to 6 , the first conductive path 20 includes a firsttubular conductor 21, an insulating coating 22 a, a protective layer 22b, flexible conductors 23 and 24, and terminals 25 and 26.

The first tubular conductor 21 is conductive and has a hollow structure.The first tubular conductor 21 is made of metal, for example, and hashigh shape retaining properties. In other words, the first tubularconductor 21 can retain its shape. The material for the first tubularconductor 21 is a metal material such as a copper-based material or analuminum-based material. The first tubular conductor 21 is formed in ashape conforming to a routing path of the wire harness unit 10 shown inFIG. 1 . The first tubular conductor 21 is bent using a pipe bender (inother words, a pipe bending device).

FIG. 4 is a cross-sectional view of the wire harness unit 10 taken alonga plane orthogonal to the lengthwise direction of the wire harness unit10. In FIG. 4 , the lengthwise direction of the first tubular conductor21 is the front-back direction of the sheet plane of FIG. 4 . Thecross-sectional shape of the first tubular conductor 21 taken along aplane that is vertical to the lengthwise direction of the first tubularconductor 21, that is, a direction in which the first tubular conductor21 extends and that is the axial direction of the first tubularconductor 21 (i.e., a lateral cross-sectional shape) is annular, forexample. Note that the cross sectional shape of the first tubularconductor 21 can be any shape. Also, with respect to the cross sectionalshape of the first tubular conductor 21, the shapes of the outercircumference and the inner circumference may be different from eachother. Also, cross sectional shapes of the first tubular conductor 21 inthe lengthwise direction may be different from each other.

The insulating coating 22 a covers the entirety of an outercircumferential surface 21 c of the first tubular conductor 21 in thecircumferential direction, for example. The insulating coating 22 a isconstituted by an insulating material such as a synthetic resin.Examples of the material for the insulating coating 22 a includesilicone resin, a synthetic resin whose main component is a polyolefinresin such as cross-linked polyethylene or cross-linked polypropylene,and the like. A single kind of material, or two or more kinds ofmaterials can be used in combination as appropriate, for the insulatingcoating 22 a. The insulating coating 22 a can be formed by performingextrusion molding (extrusion coating) on the first tubular conductor 21,for example.

The protective layer 22 b covers an inner circumferential surface 21 dof the first tubular conductor 21 over the entire circumference thereofin the circumferential direction. The protective layer 22 b is a coatingfilm made of a rigid resin, rubber, enamel, or the like. The protectivelayer 22 b prevents a coolant 73 that is supplied to the inside of thefirst tubular conductor 21 from coming into direct contact with theinner circumferential surface 21 d of the first tubular conductor 21.

As shown in FIGS. 3 and 6 , the first tubular conductor 21 includes afirst end portion 21 a and a second end portion 21 b that are two endportions of the first tubular conductor 21 in the lengthwise direction.The second end portion 21 b is an end portion that is on the oppositeside to the first end portion 21 a. The first end portion 21 a and thesecond end portion 21 b are exposed from the insulating coating 22 a.

As shown in FIGS. 3 and 5 , end portions on one side of the flexibleconductors 23 and 24 are connected to the first tubular conductor 21,and end portions on the other side of the flexible conductors 23 and 24are respectively connected to the terminals 25 and 26 shown in FIG. 2 .Specifically, the flexible conductor 23 includes a first end portion 23a that is electrically connected to the first tubular conductor 21 and asecond end portion 23 b that is electrically connected to the terminal25 shown in FIGS. 2 and 5 . The flexible conductor 24 includes a firstend portion 24 a that is electrically connected to the first tubularconductor 21 and a second end portion 24 b that is electricallyconnected to the terminal 26 shown in FIG. 2 .

The flexible conductors 23 and 24 are conductors that are more flexiblethan the first tubular conductor 21. The flexible conductors 23 and 24of the present embodiment are formed in a tubular shape. The flexibleconductors 23 and 24 are braided wires formed by braiding conductivewire strands into a tubular shape. The material for the wire strands isa metal material such as a copper-based material car an aluminum-basedmaterial.

As shown in FIG. 3 , the first tubular conductor 21 is disposed insidethe tubular first end portion 23 a of the flexible conductor 23, and thefirst end portion 21 a of the first tubular conductor 21 extends throughthe flexible conductor 23, and is disposed outside the flexibleconductor 23. A fastening band 27 a is attached to the outercircumference side of the flexible conductor 23. The flexible conductor23 is crimped to the outer circumferential surface of the first tubularconductor 21 by the fastening band 27 a. The first end portion 23 a ofthe flexible conductor 23 is electrically connected to the first tubularconductor 21 using the fastening band 27 a. Note that the first tubularconductor 21 and the flexible conductor 23 may also be connected to eachother through welding such as ultrasonic welding.

The first tubular conductor 21 is disposed inside the tubular first endportion 24 a of the flexible conductor 24, and the second end portion 21b of the first tubular conductor 21 extends through the flexibleconductor 24, and is disposed outside the flexible conductor 24. Afastening band 27 b is attached to the outer side of the flexibleconductor 24. The flexible conductor 24 is crimped to the outercircumferential surface of the first tubular conductor 21 using thefastening band 27 b. The first end portion 24 a of the flexibleconductor 24 is electrically connected to the outer circumferentialsurface of the first tubular conductor 21 by the fastening band 27 b.Note that the flexible conductor 24 and the first tubular conductor 21may be connected to each other through welding such as ultrasonicwelding.

FIG. 5 is an illustrative diagram showing connection between the firsttubular conductor, the flexible conductors, and the terminals. Notethat, in FIG. 5 , the members of the first conductive path 20 shown onthe left side of FIGS. 2 and 3 are indicated by reference signs withoutparentheses, and the members shown on the right side of FIGS. 2 and 3are indicated by reference signs in parentheses.

The terminal 25 is held by the connector 71 shown in FIGS. 1 and 2 , andconnected to the in-vehicle device M1. The terminal 25 is connected tothe second end portion 23 b of the flexible conductor 23. For example,the terminal 25 includes a pair of crimping pieces, with which theterminal 25 is crimped to the second end portion 23 b of the flexibleconductor 23. The terminal 26 is held by the connector 72 shown in FIGS.1 and 2 , and connected to the in-vehicle device M2. The terminal 26 isconnected to the second end portion 24 b of the flexible conductor 24.For example, the terminal 26 includes a pair of crimping pieces, withwhich the terminal 26 is crimped to the second end portion 24 b of theflexible conductor 24.

In addition, the second conductive path 30 includes a second tubularconductor 31, an insulating coating 32 a, a protective layer 32 b,flexible conductors 23 and 24, and terminals 25 and 26. As shown inFIGS. 4 and 6 , the second conductive path 30 is parallel with the firstconductive path 20. The second conductive path 30 is configured in asimilar manner to the first conductive path 20, and, for example, thesecond tubular conductor 31 is a component having the same model numberas the first tubular conductor 21. In addition, the insulating coating32 a covers the outer circumferential surface 31 c of the second tubularconductor 31 over the entire circumference in the circumferentialdirection. Also, the protective layer 32 b covers an innercircumferential surface 31 d of the second tubular conductor 31 over theentire circumference thereof in the circumferential direction. Similarnames and reference numerals are given to the constituent components ofthe second conductive path 30 that are similar to the constituentcomponents of the first conductive path 20, and a detailed descriptionthereof is omitted.

As shown in FIGS. 3, 4, and 6 , the cooling tube 40 is hollow. Thecooling tube 40 is more flexible than the first tubular conductor 21 andthe second tubular conductor 31. In other words, the first tubularconductor 21 and the second tubular conductor 31 30 are more rigid thanthe cooling tube 40. The material for the cooling tube 40 is a flexibleresin material such as PP (polypropylene), PVC (polyvinyl chloride), orcross-linked PE (polyethylene resin).

As shown in FIG. 6 , the cooling tube 40 includes the turnback tube 41(turnback) that links the first end portion 21 a of the first tubularconductor 21 and a first end portion 31 a of the second tubularconductor 31, an inlet tube 42 (inlet) connected to the second endportion 21 b of the first tubular conductor 21, and an outlet tube 43(outlet) connected to a second end portion 31 b of the second tubularconductor 31.

Specifically, one end of the turnback tube 41 is connected to the firstend portion 21 a of the first tubular conductor 21, and the other end isconnected to the first end portion 31 a of the second tubular conductor31. The first end portion 21 a of the first tubular conductor 21 isdisposed inside the one end portion of the turnback tube 41. A fasteningband 28 a is attached to the outer circumference side of the one endportion of the turnback tube 41. The one end portion of the turnbacktube 41 is crimped to the outer circumferential surface of the firsttubular conductor 21 using the fastening band 28 a. The first endportion 31 a of the second tubular conductor 31 is disposed inside theother end portion of the turnback tube 41. A fastening band 28 b isattached to the outer circumference side of the other end portion of theturnback tube 41. The other end portion of the turnback tube 41 iscrimped to the outer circumferential surface of the second tubularconductor 31 using the fastening band 28 b. In the present embodimentthe turnback tube 41 is crimped on the end portion side of the firsttubular conductor 21 and the second tubular conductor 31 relative to theabove-described flexible conductors 23.

The inlet tube 42 is connected to the second end portion 21 b of thefirst tubular conductor 21. The second end portion 21 b of the firsttubular conductor 21 is disposed inside an end portion of the inlet tube42. A fastening band 29 a is attached to the outer circumference side ofthe end portion of the inlet tube 42. The end portion of the inlet tube42 is crimped to the outer circumferential surface of the first tubularconductor 21 using the fastening band 29 a. In the present embodiment,the inlet tube 42 is crimped on the end portion side of the firsttubular conductor 21 relative to the above-described flexible conductor24.

The outlet tube 43 is connected to the second end portion 31 b of thesecond tubular conductor 31. The second end portion 31 b of the secondtubular conductor 31 is disposed inside the end portion of the outlettube 43. A fastening band 29 b is attached to the outer circumferenceside of an end portion of the outlet tube 43. The end portion of theoutlet tube 43 is crimped to the outer circumferential surface of thesecond tubular conductor 31 using the fastening band 29 b. In thepresent embodiment, the outlet tube 43 is crimped on the end portionside of the second tubular conductor 31 relative to the above-describedflexible conductor 24.

The coolant 73 is supplied to the inside of the first tubular conductor21 via the inlet tube 42, and the coolant 73 is supplied to the secondtubular conductor 31 via the turnback tube 41. The coolant 73 may be aliquid such as water and an antifreeze solution, or a fluid such as agas, or an air-liquid two-phase flow in which a gas and a liquid aremixed. The coolant 73 is supplied by a pump (not shown), The coolant 73supplied to the inside of the second tubular conductor 31 is dischargedvia the outlet tube 43. In this manner, the cooling tube 40,specifically the inlet tube 42, the turnback tube 41, and the outlettube 43, form a part of a circulation path through which the coolant 73is circulated. The circulation path includes the above-described pumpand a heat dissipating portion, for example. The pump pressurizes andfeeds the coolant 73 into the first tubular conductor 21 and the secondtubular conductor 31. The coolant 73 performs heat-exchange with thefirst tubular conductor 21 and the second tubular conductor 31.

The coolant 73, of which the temperature has risen as a result of heatexchange, is fed from the outlet tube 43 to the heat dissipatingportion. The heat dissipating portion cools the coolant 73 bydissipating heat from the coolant 73, of which the temperature has risenas a result of heat exchange to the outside. The cooled coolant 73 ispressurized and fed again to the first tubular conductor 21 via theinlet tube 42 by the pump. The cooling tube 40 constitutes a coolingportion for cooling the first tubular conductor 21 and the secondtubular conductor 31 using the coolant 73 circulated in this manner.

As shown in FIGS. 3 and 4 , the electromagnetic shield member 50 coverstwo conductive paths 11. The electromagnetic shield member 50 is abraided member formed by braiding metal strands into a tubular shape.The electromagnetic shield member 50 has shielding properties. Also, theelectromagnetic shield member 50 is flexible. As shown in FIG, 3, oneend of the electromagnetic shield member 50 is connected to theconnector 71, and the other end of the electromagnetic shield member 50is connected to the connector 72. Accordingly, the electromagneticshield member 50 covers the entire length of the conductive paths 11that transmit a high voltage. In this manner, the radiation ofelectromagnetic noise originating from the conductive paths 11 to theoutside is suppressed.

The exterior member 60 covers the conductive paths 11. Theabove-described cooling tube 40 is connected to the two end portions ofthe first tubular conductor 21 and the second tubular conductor 31 ofthe conductive paths 11. Accordingly, the exterior member 60 covers theconductive paths 11 and at least a portion of the cooling tube 40.

The exterior member 60 includes a tubular exterior member 61 (exteriortube), and grommets 62 and 63 respectively connected to a first endportion 61 a and a second end portion 61 b of the tubular exteriormember 61.

The tubular exterior member 61 covers portions of the outercircumferences of the first tubular conductor 21 and the second tubularconductor 31 in the lengthwise direction, for example. The tubularexterior member 61 is formed in a tubular shape in which the two endsthereof in the lengthwise direction of the first tubular conductor 21and the second tubular conductor 31 are open, for example. The tubularexterior member 61 surrounds the entirety of the outer circumferences ofthe first tubular conductor 21 and the second tubular conductor 31 inthe circumferential direction, for example. The tubular exterior member61 of the present embodiment is formed in a cylindrical shape. Thetubular exterior member 61 has a bellows structure in which, forexample, annular protruding portions and annular recessed portions arealternately arranged along the axis direction (lengthwise direction)thereof in which the central axial line of the tubular exterior member61 extends. Examples of the material for the tubular exterior member 61include a conductive resin material and a non-conductive resin material.Examples of the resin material include a synthetic resin such aspolyolefin, polyimide, polyester, and ABS resin. The tubular exteriormember 61 of the present embodiment is a corrugated tube made of asynthetic resin.

The grommet 62 is formed in a substantially tubular shape. The grommet62 is made of rubber, for example. The grommet 62 spans between theconnector 71 and the tubular exterior member 61. The grommet 62 isfastened and fixed to the outer surface of the connector 71 by afastening band 64 a so as to be in close contact therewith. Also, thegrommet 62 is fastened and fixed to the outer side of the first endportion 61 a of the tubular exterior member 61 by a fastening band 64 bso as to be in close contact therewith. As shown in FIG. 3 , theturnback tube 41 of the cooling tube 40 is disposed inside the grommet62.

The grommet 63 is formed in a substantially tubular shape. The grommet63 is made of rubber, for example. The grommet 63 spans between theconnector 72 and the tubular exterior member 61. The grommet 63 isfastened and fixed to the outer surface of the connector 72 by afastening band 65 a so as to be in close contact therewith. Also, thegrommet 63 is fastened and fixed to the outer side of the second endportion 61 b of the tubular exterior member 61 by a fastening band 65 bso as to be in dose contact therewith. Through holes 63 a extendingthrough the grommet 63 are formed in the grommet 63. The through holes63 a bring the inside and the outside of the grommet 63 intocommunication.

In the present embodiment, the two through holes 63 a are formed in thegrommet 63, and the inlet tube 42 is inserted into one through hole 63a, and the outlet tube 43 is inserted into the other through hole 63 a.The through holes 63 a are formed so as to be in close contact with theouter circumferential surface of the inlet tube 42 or the outlet tube 43that is inserted thereinto. The inlet tube 42 and the outlet tube 43extend through the electromagnetic shield member 50, and are led fromthe through holes 63 a of the grommet 63 to the outside of the grommet63.

Operation

Next, operation of the wire harness unit 10 of the present embodimentwill be described.

The wire harness unit 10 includes the conductive paths 11 that conductelectricity between the in-vehicle devices M1 and M2, and the coolingtube 40 constituting the cooling portion that cools the conductive paths11. The conductive paths 11 respectively include the first tubularconductor 21 and the second tubular conductor 31 that are conductive andhollow. The cooling tube 40 is more flexible than the first tubularconductor 21 and the second tubular conductor 31, and is separate fromthe first tubular conductor 21 and the second tubular conductor 31. Thecoolant 73 can flow inside the first tubular conductor 21, the secondtubular conductor 31, and the cooling tube 40. The cooling tube 40includes the turnback tube 41 that links the first end portion 21 a ofthe first tubular conductor 21 and the first end portion 31 a of thesecond tubular conductor 31, the inlet tube 42 connected to the secondend portion 21 b of the first tubular conductor 21, and the outlet tube43 connected to the second end portion 31 b of the second tubularconductor 31.

The coolant 73 flows inside the first tubular conductor 21 and thesecond tubular conductor 31 via the cooling tube 40. At this time, thecoolant 73 flows through the inlet tube 42, the first tubular conductor21, the turnback tube 41, the second tubular conductor 31, and theoutlet tube 43, in the stated order. The first tubular conductor 21 andthe second tubular conductor 31 are cooled through heat exchange withthe flowing coolant 73. In this manner, the first tubular conductor 21and the second tubular conductor 31 can be cooled from the inside.

Compared to a braided wire formed by twisting together a plurality ofmetal strands having the same cross sectional area and a single corewire having a solid structure, the first tubular conductor 21 and thesecond tubular conductor 31 have a larger outer circumference. In otherwords, the first tubular conductor 21 and the second tubular conductor31 have a larger area on the outer circumferential side compared to abraided wire and a single core wire. Accordingly, since heat can bedissipated outward from a larger area, heat dissipation properties canbe improved.

The wire harness unit 10 includes the protective layers 22 b and 32 bthat respectively cover the inner circumferential surfaces 21 d and 31 dof the first tubular conductor 21 and the second tubular conductor 31,over the entire circumferences thereof in the circumferential direction.The protective layers 22 b and 32 b make it possible to prevent thecoolant 73 that is supplied to the inside of the first tubular conductor21 and the second tubular conductor 31, from coming into direct contactwith the inner circumferential surfaces 21 d and 31 d of the firsttubular conductor 21 and the second tubular conductor 31, respectively.

The conductive paths 11 include the flexible conductors 23 and 24respectively connected to the first tubular conductor 21 and the secondtubular conductor 31. The flexible conductors 23 and 24 are moreflexible than the first tubular conductor 21 and the second tubularconductor 31. Accordingly, dimensional tolerance of the conductive paths11 can be absorbed. Also, when the vehicle V vibrates, positionaldeviation between the parts connected to two ends of the flexibleconductors 23 and 24 due to the vibration can be absorbed. In thepresent embodiment, for example, positional deviation between the firsttubular conductor 21 and the connectors 71 and 72, that is, between thefirst tubular conductor 21 and the in-vehicle devices M1 and M2 can beabsorbed. Accordingly, loads applied to the connectors 71 and 72 and theterminals 25 and 26 can be reduced.

Also, as shown in FIG. 3 , the length L1 of the first tubular conductor21 and the second tubular conductor 31 is greater than the lengths L2and L3 of the flexible conductors 23 and 24. The lengths L2 and L3 ofthe flexible conductors 23 and 24 are lengths indicating the range inwhich the conductive paths 11 can be bent utilizing the flexibility ofthe flexible conductors 23 and 24. In the present embodiment, thelengths L2 and L3 are the distance between the connector 71 and thefirst tubular conductor 21 and the second tubular conductor 31, and thedistance between the connector 72 and the first tubular conductor 21 andthe second tubular conductor 31, respectively. Therefore, sections inwhich the coolant 73 is in contact with the first tubular conductor 21and the second tubular conductor 31 are long, that is, sections whereheat exchange takes place between the coolant 73 and the first tubularconductor 21 and the second tubular conductor 31 can be increased inlength, thus making it possible to further cool the first conductivepath 20 and the second conductive path 30. Note that the lengths L2 andL3 of the flexible conductors 23 and 24 can be equal to or differentfrom each other.

The electromagnetic shield member 50 covers the two conductive paths 11.The electromagnetic shield member 50 is a braided member formed bybraiding metal strands into a tubular shape. For this reason, radiationof the electromagnetic noise originating from the conductive paths 11 tothe outside can be suppressed. Also, for this reason, the cooling tube40, specifically the inlet tube 42 and the outlet tube 43, can be ledout from the electromagnetic shield member 50 at intermediate positionsof the electromagnetic shield member 50. Thus, the inlet tube 42 and theoutlet tube 43 can be easily led to the outside of the wire harness unit10, and constituent members for circulating the coolant 73 can be easilyconnected to the first tubular conductor 21 and the second tubularconductor 31.

The wire harness unit 10 includes the exterior member 60 for covering atleast a portion of the cooling tube 40 and the conductive paths 11. Theexterior member 60 includes a tubular exterior member 61, and grommets62 and 63 respectively connected to a first end portion 61 a and asecond end portion 61 b of the tubular exterior member 61. The coolingtube 40, specifically the inlet tube 42 and the outlet tube 43 extendthrough the grommet 63. In this manner, since the inlet tube 42 and theoutlet tube 43 extend through the grommet 63, and are led to the outsideof the wire harness unit 10, degradation of the water blockingproperties of the wire harness unit 10 can be suppressed.

As described above, according to the present embodiment, the followingeffects are achieved.

(1) The coolant 73 can flow inside the first tubular conductor 21 andthe second tubular conductor 31, and inside the cooling tube 40. Forthis reason, the first tubular conductor 21 and the second tubularconductor 31 can be cooled from the inside, making it possible toimprove the cooling efficiency. Moreover, the cooling tube 40 includesthe turnback tube 41 that links the first end portion 21 a of the firsttubular conductor 21 and the first end portion 31 a of the secondtubular conductor 31, and thus, for example, compared with a case wherethe cooling tube 40 does not include the turnback tube 41, it ispossible to reduce the number of inlets and outlets for the coolant 73,specifically, the number of inlet tubes 42 and outlet tubes 43. Thus, aconnection structure for connection between the cooling tube 40 and thepump can be simplified. In addition, for example, compared with a casewhere the cooling tube 40 does not include the turnback tube 41, it ispossible to reduce the number of inlet tubes 42 and outlet tubes 43 andthe number of components.

(2) The plurality of conductive paths 11 include the first conductivepath 20 and the second conductive path 30. The number of conductivepaths included in the plurality of conductive paths 11 is an evennumber, and thus the inlet and the outlet for the coolant 73,specifically, the inlet tube 42 and the outlet tube 43 can be naturallypositioned on the second end portion 21 b side of the first tubularconductor 21, and the inlet and the outlet for the coolant can be easilypositioned close to each other. That is to say, a situation is avoidedwhere the positions of the inlet tube 42 and the outlet tube 43 for thecoolant 73 are spaced far apart from each other when, for example, thenumber of conductive paths 11 is three, which is an odd number, thecooling tube 40 includes two turnback tubes 41, and the outlet tube 43is connected to a first end portion of a third tubular conductor of athird conductive path. Thus, for example, it is possible to easily setthe positions of the inlet tube 42 and the outlet tube 43 close to eachother, and to reduce a routing space and the like for connection to apump, for example.

(3) The turnback tube 41 is disposed inside the grommet 62, and thus,for example, the turnback tube 41 can be easily housed. Even in a casewhere, for example, the turnback tube 41 is configured such that itcannot be sharply bent, and a large space is required, such a case canbe easily addressed without increasing the entire size of the tubularexterior member 61. Moreover, for example, if the grommet 62 is shapedsuch that the size thereof increases toward a member that is connectedthereto, the turnback tube 41 can be easily housed in a large space.

(4) The protective layers 22 b and 32 b that cover the innercircumferential surfaces of the first tubular conductor 21 and thesecond tubular conductor 31 are provided, and thus the protective layer22 b and 32 b make it possible to prevent the coolant 73 that issupplied to the inside of the first tubular conductor 21 and the secondtubular conductor 31 from coming in to direct contact with the innercircumferential surfaces of the first tubular conductor 21 and thesecond tubular conductor 31.

(5) As a result of the flexible conductors 23 and 24 being connected tothe end portions of the first tubular conductor 21 and the secondtubular conductor 31, dimensional tolerance of the conductive paths 11can be absorbed. Further, this configuration is a counter measureagainst swinging that occurs while a vehicle is travelling.

(6) The first tubular conductor 21 and the second tubular conductor 31are longer than the flexible conductors 23 and 24, and thus sections inwhich heat exchange takes place between the coolant 73 and the firsttubular conductor 21 and the second tubular conductor 31 are long,making it possible to further cool the first tubular conductor 21 andthe second tubular conductor 31.

(7) The electromagnetic shield member 50 is a braided member formed bybraiding metal strands into a tubular shape, and the cooling tube 40,specifically the inlet tube 42 and the outlet tube 43, extend throughthe braided member, and thus both the shielding properties forsuppressing radiation of electromagnetic noise originating from theconductive paths 11 to the outside and an improvement in the ease ofassembly of the cooling portion can be achieved.

(8) Since the cooling tube 40, specifically the inlet tube 42 and theoutlet tube 43, extend through the grommet 63 so as to be led to theoutside, degradation of the water blocking properties of the wireharness unit 10 can be suppressed.

Variations

The present embodiment can be modified and implemented as follows. Thepresent embodiment and the variations below may be implemented incombination with each other as long as no technical contradictionsarise.

As shown in FIGS. 7 and 8 , the flexible conductors 23 and 24 may covera portion of the cooling tube 40. Specifically, the first end portion 23a of the tubular flexible conductor 23 covers the first end portion 21 aof the first tubular conductor 21, the end portion of the turnback tube41 connected to the first end portion 21 a, and the fastening band 28 athat crimps the turnback tube 41 to the first tubular conductor 21.Similarly, the first end portion 24 a of the tubular flexible conductor24 covers the second end portion 21 b of the first tubular conductor 21,the end portion of the inlet tube 42 connected to the second end portion21 b, and the fastening band 29 a that crimps the inlet tube 42 to thefirst tubular conductor 21. The inlet tube 42 is drawn out from a gapbetween metal strands of a braided member that is the flexible conductor24, to the outside of the flexible conductor 24. In addition, as amatter of course, the second conductive path 30 side may be configuredin a similar manner.

In the above embodiment, the number of conductive paths included in theplurality of conductive paths 11 is an even number, but there is nolimitation thereto, and the number of conductive paths may be an oddnumber of three or more, or may be an even number of four or more. Aconfiguration may be adopted in which, for example, the number ofconductive paths 11 is three, and the cooling tube 40 includes twoturnback tubes 41. Moreover, a configuration may also be adopted inwhich, for example, the number of conductive paths 11 is four, forexample, and the cooling tube 40 includes three turnback tubes 41.

-   -   In the above embodiment, the turnback tube 41 is configured to        be disposed inside the grommet 62, but there is no limitation        thereto, and the turnback tube 41 may be configured to be        disposed at another location such as inside the tubular exterior        member 61.    -   In the above embodiment, the cooling tube 40 is led out from the        grommet 63, that is, the cooling tube 40 is passed through        grommet 63. However, the cooling tube 40 may be led out from the        connector 72. By doing so, the first tubular conductor 21, the        second tubular conductor 31, and the connector 72 can be cooled.    -   The electromagnetic shield member 50 of the above embodiment may        be a piece of metal tape or the like. An insulation layer may be        provided on the inner circumferential surface of the        electromagnetic shield member 50.    -   Twisted wires formed by twisting a plurality of metal strands        together may be used as the flexible conductors 23 and 24 of the        above embodiment.    -   In contrast to the above embodiment, a configuration is also        possible in which, for example, the tubular flexible conductors        23 and 24 are formed in a sheet-like shape, and are thereby        electrically connected to the first tubular conductor 21 and the        second tubular conductor 31. The flexible conductors 23 and 24        may or may not be wrapped around the cooling tube 40. If the        flexible conductors 23 and 24 are wrapped around the cooling        tube 40, the cooling tube 40 can be easily drawn out from a gap        between the flexible conductors 23 and 24 overlaid in the manner        of a sushi roll.    -   Although the above embodiment and the variations described that        the shape of the flexible conductor 23 on the connector 71 side        and the shape of the flexible conductor 24 on the connector 72        side are the same, their shapes may be different from each        other.    -   As shown in FIGS. 3, 5, and 6 , each flexible conductor 23        according to the embodiment may include first and second        extended leading end portions respectively drawn out from the        first and second end portions 23 a and 23 b of the flexible        conductor 23 outward in the radial direction. If, for example,        the flexible conductor 23 is a tube made of braided wires, each        of the extended leading end portions of the flexible conductor        23 may be a tubular, belt-like, or linear braided wire lead        formed by reducing the diameter of, transforming, or processing        a length portion that excludes the first and second end portions        23 a and 23 b of the flexible conductor 23. The same applies to        the flexible conductor 24.    -   The first tubular conductor 21 and the second tubular conductor        31 may have a length corresponding to the routing path        corresponding to substantially the entire length of the wire        harness unit 10 excluding the connectors 71 and 72 on the two        end of the wire harness unit 10 and the lengths L2 and L3. The        first tubular conductor 21 and the second tubular conductor 31        may be rigid to the extent that the length (for example, bending        degree) and/or thickness of the first tubular conductor 21 and        the second tubular conductor 31 does not change between        immediately before and after the wire harness unit 10 is mounted        in a vehicle.    -   As shown in FIG. 3 , the wire harness unit 10 according to a        preferable example can include the first tubular conductor 21,        the second tubular conductor 31, a plurality of cooling tubes        41, 42, and 43, the plurality of flexible conductors 23 and 24,        and the electromagnetic shield member 50. The first tubular        conductor 21 and the second tubular conductor 31 each may have        an inner pipe space, a first opening end, a second opening end,        and a pipe length defined by the first opening end and the        second opening end. The first tubular conductor 21 and the        second tubular conductor 31 may be disposed side by side over        the entire lengths thereof. A configuration may also be adopted        in which, for example, the first opening end of the first        tubular conductor 21 and the first opening end of the second        tubular conductor 31 are disposed side by side, and the second        opening end of first tubular conductor 21 and the second opening        end of the second tubular conductor 31 are disposed side by        side. The cooling tubes 41, 42, and 43 may each include an inner        tube space and two tube end portions. The inner tube spaces of        the first tubular conductor 21 and the second tubular conductor        31 and inner tube spaces of the plurality of cooling tubes 41,        42, and 43 are in communication with each other so as to form a        cooling circuit. A configuration can be adopted in which the        cooling tube 41 is connected to the first pipe opening end of        the first tubular conductor 21 and the first pipe opening end of        the second tubular conductor 31, and extends in a U-shape        between the first pipe opening end of the first tubular        conductor 21 and the first pipe opening end of the second        tubular conductor 31. The U-shaped cooling tube 41 may be        disposed inside the electromagnetic shield member 50, outside        the flexible conductor 23 associated with the first tubular        conductor 21, and outside the flexible conductor 23 associated        with the second tubular conductor 31. The U-shaped cooling tube        41 is not covered by the flexible conductor 23 associated with        the first tubular conductor 21 and the flexible conductor 23        associated with the second tubular conductor 31, and does not        need to extend through the electromagnetic shield member 50 in a        radial direction. The cooling tubes 42 and 43 may be        respectively connected to the second pipe opening end of the        first tubular conductor 21 and the second pipe opening end of        the second tubular conductor 31, and extend side by side from        the second pipe opening end of the first tubular conductor 21        and the second pipe opening end of the second tubular conductor        31 in the same lengthwise direction. The cooling tubes 42 and 43        may extend radially outward side by side from the        electromagnetic shield member 50, in the vicinity of the second        pipe opening ends of the first tubular conductor 21 and the        second tubular conductor 31. The cooling tubes 42 and 43 are not        covered by the flexible conductor 24 associated with the first        tubular conductor 21 and the flexible conductor 24 associated        with the second tubular conductor 31, and may extend through the        electromagnetic shield member 50 in a radial direction. The        cooling tubes 42 and 43 may extend through the electromagnetic        shield member 50 radially at a predetermined length position        that is far from the first pipe opening ends of the first        tubular conductor 21 and the second tubular conductor 31, and is        close to the second pipe opening ends of the first tubular        conductor 21 and the second tubular conductor 31.    -   As shown in FIG. 4 , in the wire harness unit 10 according to a        preferable example, the inner circumferential pipe surface of        the first tubular conductor 21 may be covered by the protective        layer 22 b extending over the entire length of the first tubular        conductor 21. The inner circumferential pipe surface of the        second tubular conductor 31 may be covered by the protective        layer 32 b extending over the entire length of the second        tubular conductor 31. The protective layers 22 b and 32 b may        end at the opening ends on the two sides of the corresponding        tubular conductors 21 and 31, and the protective layers 22 b and        32 b do not need to extend outward from the opening ends on the        two sides of the corresponding tubular conductors 21 and 31 in        the lengthwise direction. The protective layers 22 b and 32 b        may be a coating, a lining, or a processed surface layer        sometimes referred to as a coating, extending over the entire        length of the corresponding tubular conductors 21 and 31.

1. A wire harness unit comprising: a plurality of conductive paths forconducting electricity between in-vehicle devices; and a cooling tubethrough which a coolant is able to flow for cooling the plurality ofconductive paths, wherein: the plurality of conductive paths include afirst conductive path and a second conductive path parallel with thefirst conductive path, the first conductive path includes a firsttubular conductor that is conductive and hollow, the second conductivepath includes a second tubular conductor that is conductive and hollow,each of the first tubular conductor and the second tubular conductorincludes a first end and a second end that is on an opposite side to thefirst end, the cooling tube is more flexible than the first tubularconductor and the second tubular conductor, and is separate from thefirst tubular conductor and the second tubular conductor, and thecooling tube includes a turnback that links the first end of the firsttubular conductor and the first end of the second tubular conductor, aninlet connected to the second end of the first tubular conductor, and anoutlet connected to the second end of the second tubular conductor. 2.The wire harness unit according to claim 1, wherein a number ofconductive paths included in the plurality of conductive paths is aneven number.
 3. The wire harness unit according to claim 1, furthercomprising an exterior cover for covering the conductive paths, wherein:the exterior cover includes an exterior tube and a grommet that isconnected to an end of the exterior tube, and the turnback is disposedinside the grommet.
 4. The wire harness unit according to claim 1,further comprising protective layers that respectively cover innercircumferential surfaces of the first tubular conductor and the secondtubular conductor.
 5. The wire harness unit according to claim 1,wherein: the first conductive path and the second conductive path eachinclude a flexible conductor and a terminal, the flexible conductorincludes a first end that is electrically connected to the first tubularconductor or the second tubular conductor, and a second end that iselectrically connected to the terminal, and the flexible conductor ismore flexible than the first tubular conductor and the second tubularconductor.
 6. The wire harness unit according to claim 5, wherein eachof the first tubular conductor and the second tubular conductor islonger than the flexible conductor.
 7. The wire harness unit accordingto claim 1, further comprising an electromagnetic shield for covering atleast a portion of the cooling tube, the first tubular conductor, andthe second tubular conductor, the electromagnetic shield is a braidedmember formed by braiding metal strands, and the cooling tube extendsthrough the braided member.
 8. The wire harness unit according to claim1, further comprising an exterior cover for covering the conductivepaths, wherein: the exterior cover includes an exterior tube and agrommet connected to an end of the exterior tube, and the cooling tubeextends through the grommet.